A bioreactor typically comprises a bioreaction chamber for housing a biologically active environment. Within the bioreaction chamber, the bioreactor establishes and maintains the environment to optimize the desired biochemical activity. For example, the bioreactor may regulate the amount of Oxygen in the environment. The desired biochemical reaction is used to process an influent, for example, wastewater. Once processed, the bioreactor outputs effluent. Indeed, a common rudimentary bioreactor is a septic tank.
In applications where traditional treatment of wastewater, for example, sewage infrastructure systems, and septic tanks, may be impractical or insufficient to achieve a desired treatment objective, bioreactors may be used. For example, U.S. Patent Application Publication No. 2006/0096918 to Semmens discloses a bioreactor for treatment of wastewater. The bioreactor includes hollow fiber membranes (HFMs) in the bioreaction chamber. Gases are passed through the HFMs to encourage bacteria and other microorganisms to form a layer on the surfaces of the HFMs.
This layer of microorganisms is called a biofilm and may be used to treat wastewater by processing certain compounds. The bioreactor of Semmens passes Oxygen through the HFMs to encourage growth of more advanced microorganisms on the surface of the HFMs. The bioreactor may alternatively pass other gases through the HFMs, for example, air and Hydrogen. Moreover, in one embodiment, Oxygen and Hydrogen may be flowed sequentially by using a series of bioreactors. In other words, the Oxygen is flowed in the bioreaction chamber of the first bioreactor. The effluent of the first bioreactor is the influent of the second bioreactor. Hydrogen is flowed through the HFMs of the second bioreactor. A drawback to this approach is the use of two bioreactors may be undesirable for applications where space is limited, for example, a spacecraft.
Another bioreactor for processing of wastewater is disclosed in U.S. Pat. No. 7,303,677 to Cote et al. This bioreactor includes a weave of HFMs within the bioreaction chamber for growing biofilm. Oxygen, or in the alternative, Hydrogen, is passed through the HFMs to encourage the desired biochemical reaction.